Another question, create closed polylines (lines), how to?

Hy again,

delaunay mesh was not good solution for this, but i have another question?

How to make closed polylines (regions) from lines that are exploded for example?

Replies to This Discussion

Permalink Reply by Pieter Segeren on July 15, 2015 at 1:48pm

Hi Andy,
it looks like the line networks that you are using now are quite different than the ones you described earlier, I think the confusion (yours and mine/ours) is due to that (the 'rules' went out the window).

About the numbers in my definition: leave them as they are.
You can use the Slider to iterate through the created closed polylines lists (provided that you stick to the 'established rules'. Otherwise this definition isn't useful/will cause confusion/won't work)

Permalink Reply by andy on July 15, 2015 at 2:29pm

Yes i knew it's gonna be confusing with some objects.

Try this example with this method and this is what you will get.

If you have some lines directly one above or bellow another.

Attachments:

example1.3dm, 41 KB
RoofOutlineFromLines_PSG.gh, 25 KB

Permalink Reply by andy on July 16, 2015 at 1:06am

So, is there a way to prevent confusion in this case, or this reqires manual scripting.

Permalink Reply by nikos tzar on July 16, 2015 at 5:29am

Hello Andy,

I am afraid you are discarding solutions without putting some effort into understanding them first...

The thing you say with the 12 edges doesn't make much sense. This is exactly the reason Matt put this slider there. No need to add support lines, you just have to make sure the slider's value is greater than the maximum number of edges you have... Just set it to something high and leave it there! (this applies to both suggestions from Matt and me)

I can't be 100% sure because I don't have Python installed, but I believe Matt's first solution has given you what you want. You just need to extract the brep's faces into curves, with something like this at the end of his definition:

As for my suggestion, with [MeshMerge] you are right, the correct link to "mesh tools" is provided here: http://www.grasshopper3d.com/photo/mesh-tools (you need to join the milkbox group first)

Permalink Reply by andy on July 16, 2015 at 8:34am

It means you don't understand this because you didn't try this, right?

i'm not saying that with no reason.

That's why i asked is there maybe way to make outline edges (closed polylines) rather then creating surfaces from lines, like i told that i don't need necessary meshes.

But it turned out that creating outlines it has confusion with shifting control points from planar way to their original control points, what i posted in previous post.

Permalink Reply by Matt Gaydon on July 16, 2015 at 9:03am

Hi Andy,

Can you post up your last example with the green lines (Won't let me reply to that post), I think the problem is as soon as the curve outlines become non planar you can't create Single Meshes or Surface. I am still working out a few bugs in the last example you posted, when I get time.. will have another look after hours.

Matt

Permalink Reply by andy on July 16, 2015 at 11:00am

Last example and gh file. Green lines are not included in gh file, (you need to include them), and there is another problem area, bottom surface, you will notice.

Attachments:

example_2.3dm, 569 KB
PITCHEDROOFS_example.gh, 12 KB

Permalink Reply by Matt Gaydon on July 16, 2015 at 12:35pm

This New example seems to run fine with no additional curves added using the Second code i posted. [Projected Pitches.gh] To create outlines. Still have problems finding a way to solve overlapping over different roofs in Example 1. As it contains no planar roof sections so gives extra crvs if you use the mesh/brep option Code 1[Pitched Roofs].

Does it all need to be coded. As maybe it only the 'broken' (No Planar ones that need making manually with Merge Surface command in Rhino with all settings at 0

Permalink Reply by nikos tzar on July 16, 2015 at 12:13pm

Hello Andy,

the main problem (as Matt noticed) seems to be that some of the polylines you want to create are not actually planar.

Since your design resembles inclined roofs and since you didn't post any file until late in the conversation, we wrongly assumed the "roof's" surfaces would/should be planar...

Anyway, having this issue in mind, here is another approach, using the shortest walk plugin.

The logic of the definition is that for each line you find the shortest path between it's endpoints, that is not the line itself.

Hopefully this will create all the polylines you need (it does in your last example, I am not sure it will work on any case) and then all you have to do is remove the duplicate polylines (there will be quite a few of them):

Attachments:

example_2-nt.3dm, 37 KB
shortest-walk.gh, 11 KB

Permalink Reply by andy on July 17, 2015 at 5:05am

The shortest walk works good.

There is no need for anything else (with weavebird or something).

Permalink Reply by nikos tzar on July 17, 2015 at 6:04am

Great!

Thank you for letting us help!

Permalink Reply by andy on July 18, 2015 at 1:02pm

Hy again, just one more question.

Like i said now it works good, but i just tested a little bit with a larger number of lines,

let's say when i explode all it has about 3500 lines (and it takes about one minute to process), but if i copy this all again once it has 7000 lines and when i put all this lines the process freezes for some reason. Is this have to be like that or it's about computer, all some other reason...?